1. Field of the Invention
The present invention relates to porting of the propellant gas of a firearm and, more particularly, to the reduction of gun rise and muzzle jump of a firearm through upward porting of the propellant gas.
2. Description of the Prior Art
Handheld firearms, when fired, exhibit a phenomenon usually described as muzzle jump. The common intuitive understanding of the phenomenon has provided guidance for gunsmiths and inventors who have generated numerous devices intended to reduce the magnitude of the normal upward motion of the muzzle by venting the propellant gas upwardly at the muzzle to create a downward thrust on the muzzle. The ultimate purpose of these devices was and is that of permitting firing a series of shots more rapidly and accurately.
A more complete understanding of the phenomena which interfere with the rapid shooting of the firearm is required to more accurately address a solution. Central to this increased understanding is the concept that the phenomenon of gun rise is separate from the phenomenon of muzzle jump. Gun rise is an upward motion of the entire firearm when it is fired which would occur even if muzzle jump were completely eliminated. This concept of gun rise is not addressed in the known prior art. Gun rise is a small upward motion of the firearm which interferes with the aiming of the firearm when several shots are fired from the firearm in quick succession. Gun rise motion occurs after the well known muzzle rise motion. Virtual elimination of gun rise permits the shooter to fire a series of shots rapidly and more accurately than is otherwise possible.
The known prior art is directed to reduction or elimination of muzzle jump. Generally the muzzle jump is sought to be countered by the installation of ports directly into the barrel near the muzzle to vent the propellant gas directly into the atmosphere. Numerous variants of such vents exist. Radial (upward, lateral and/or downward) porting of propellant gas from the barrel near the muzzle through simple ports allegedly improves accuracy or allegedly reduces recoil by reducing the propellant gas pressure in the barrel before the projectile leaves the muzzle. Upward porting of the barrel near the muzzle with side by side paired ports with each port of each pair being equally spaced from a vertical plane coincident with the axis of the barrel is a well known variant which allegedly helps reduce muzzle jump. In some embodiments, the propellant gas may be vented radially (laterally), without upward venting at the muzzle. Another approach includes using radial (lateral) ports disposed in the barrel between the chamber and muzzle to vent the propellant gas posteriorly into the atmosphere to help reduce recoil. Finally, it is known to use radially oriented, backward facing and diverging ports spaced from near the chamber to near the muzzle to vent the propellant gas simultaneously in different directions.